The Birthday Date Game
Birthday Date is a simple but not easy challenge to promote lateral thinking and inspire creativity in small teams.
Start by laying the five cards in order – A B C D E – on a table or on the floor in front of your group. Every card has 20 numbers on it – all of them chosen from 1 to 31, hence the birth date connection.
You can download the cards from this link.
Invite one volunteer to tell you which one or more cards has their birth date on it (not month or year.) Their date will always appear on at least one card, and maybe on all five cards.
Applying a simple solution you easily predict their birth date accurately. As an example, tell the group the volunteer’s date of birth, people will be surprised!
Repeat this exercise with other volunteers. At this point, explain to your group that to solve this problem/puzzle, they need to think laterally.
There is something very obvious that will easily help someone in the know to solve the puzzle every time, and quickly. Encourage your group to test some ‘theories’ and see if they fit with your answers.
After a few minutes, and many failed attempts to find a solution, you will more than likely need to share some clues:
- What numbers only appear on one card?
- What number or numbers appear on every card?
- What relationship do these numbers have in connection to each other?
Within five or so minutes, reveal the solution to your group.
The number which appears in the top left-hand corner of each card is the key. The solution is always the sum of these (top left-hand corner) numbers of the nominated cards.
Moment of Reflection
- Did you discover the formula to calculate the birth dates quickly?
- What did you tell yourself as the activity progressed? Good or bad?
- When you finally understood the formula, how did you feel?
- The formula in this puzzle is extremely subtle until it becomes very obvious. What elements of your life do you think remain hidden to the group?